Highway truck with self-contained refrigeration systems



Feb. 2, 1954 1-. SELLSTROM 2,667,761

HIGHWAY TRUCK WITH SELF-CONTAINED REFRIGERATION SYSTEMS Filed NOV. 5, 1951 4 Sheets-Sheet l INVENTOR. fiZUEX/CE' 7: SEZLSTQOM QTTOEA/EV L. T. SELLSTROM Feb. 2, 1954 HIGHWAY TRUCK WITH SELF-CONTAINED REFRIGERATION SYSTEMS 4 Sheets--Shset 2 Filed NOV. 5, 1951 umgl HUQAWQM INVENTOR.

Md/QEVCE Z 5666679014 nrmeA/B Feb. 2, 1954 T. SELLSTROM ,6 7,7

HIGHWAY TRUCK WITH SELF-CONTAINED REFRIGERATION SYSTEMS Feb. 2, 1954 'r. SELLSTROM HIGHWAY TRUCK WITH SELF-CONTAINED REFRIGERATION SYSTEMS :4 Sheets-Sheet 4 Filed Nov. 5. 1951 w NQMWN N mo.

INVENTOR. ZHZUQEK/CE 7-" ((579041 Patented Feb. 2, 1954 HIGHWAY TRUCK WITH SELF-CONTAINED REFRIGERATION SYSTEMS Lawrence '1. Sellstrom, Los Angeles, Calif., as-

signor to Knudsen Creamery Co. of California, Los Angeles, Calif., a corporation of California Application November 3, 1951, Serial No. 254,674

6 Claims.

This invention relates to refrigerated highway trucks and particularly to a highway truck embodying a self-contained refrigeration unit therein.

The problem to the solution of which the present invention was directed involves the refrigeration of a particular type of refrigerated truck body to which all standard refrigerating units are, for one reason or another, inapplicable. The truck body in question is of the type formerly refrigerated by ice carried in troughs just within opposite sides of the body and is relatively low, being only slightly higher than the drivers cabin and which has no place on the exterior of the body on which a refrigeration unit might be practically applied. This type of body carries a series of narrow full-height doors opening from opposite sides of the truck body throughout the length of the latter so that access may be had through a corresponding opposite pair of said doors to the boxes or bottle cases contained in each of a series of transverse compartments into which said body is divided.

The objects of the invention embrace the provision of a self-contained refrigeration system for such a truck which would not increase the width, height or length of the body; one which would weigh substantially less than the amount of ice previously recited for the refrigeration of said body; a system which would keep all sections of the body cold thereby eliminating hot spots; that would provide adequate refrigeration to keep the products in the truck body at approximately 40 F. twenty-four hours each day; which must be operable under its own power while said truck is travelling and be operable when said truck is stored at night by connection with any standard electric service outlet; and that will not represent either a nuisance or a safety hazard to the general public or to the truck operator.

The manner of accomplishing the foregoing objects as well as further objects and advantages will be made manifest in the accompanying drawings in which Fig. 1 is a diagrammatic, side elevational view of a preferred embodiment of the invention.

Fig. 2 is a rear elevational view of Fig. 1.

Fig. 3 is an enlarged transverse fragmentary sectional view taken on the line 3-3 of Fig. 1 and illustrating the self-contained refrigeration unit of the invention.

Fig. 4 is a fragmentary vertical sectional view taken on the line l4 of Fig. 3.

Fig. 5 is a fragmentary vertical sectional view taken on the line 55 of Fig. 3.

Fig. 6 is a diagrammatic perspective view 11- lustrating the refrigeration system of the invention.

Referring specifically to the drawings and particularly to Figs. 1 and 2, the invention is there shown as preferably embodied in a highway truck [8 having an automotive chassis H including a frame l2 mounted on front wheels 13 and rear drive wheels l6 and having a drivers cabin is for accommodating the driver of the truck. The truck 16 also includes a cold box 26 all the walls 2| of which are formed of spaced sheets of metal 22 and 23, the space between which is filled with heat insulating material 24 (Fig. 4). The walls 2i of box 2%) include a front wall 25 (Fig. 1), a bottom wall 26 (Fig. 4) a rear wall 2?, a top wall 28 and side walls 29 and 30.

The side Walls 29 and 30 are formed by a series of narrow, full-height doors 3| which are hingedly mounted back to back along adjacent vertical edges to close closely spaced vertical door openings formed in the side walls 29 and 33. The door openings thus formed in side walls 29 are directly opposite corresponding door openings in side wall 30, thereby providing ready access separately to either end of each of a series of transverse compartments 32 into which the interior of cold box 20 is divided by a series of cold plates 33 (Fig. 4) which are supported by vertical bars 34 and horizontal pairs of angle irons 35 which act as supporting rails for boxes 36 of uniform size in which the product is packed for conveniently loading the same into and removing it from the truck Hi.

In order to accommodate the axle structure on which the rear drive wheels I4 are mounted, the bottom wall 26 is higher, by approximately the height of a single box 36, in the two compartments 32 disposed over wheels Hi. This causes the doors 3! for these two compartments to be correspondingly shorter than the other doors 3!.

The lower edge of rear wall 27 connects with a short horizontal wall 45 the inner edge of which is joined by a short vertical wall 46 to the rear edge of bottom wall 26 (Fig. 4). An insulated transverse recess 47 is thus formed which extends entirely across the rear lower corner of the cold box 20 for the reception of a refrigerant compressing unit 48. The unit 48 is mounted on a structural steel frame 49 which extends across and is fixed upon longitudinal channel members 50 of the chassis frame l2 (Fig. 3).

The rearmost doors 5| (of the side doors 3|) have upper portions 52 thereof of double-walled upper portions lie opposite and close opposite ends of transverse compartment 53 (of the compartments 32) which lies just above the horizontal wall 35. Lower portions of the doors 5i are formed of sheet metal 5d having louvres which sheet metal lies in the planes of the outer faces of cold box side walls 29 and 36 and permits the passage of air into and from the recess ill in which the unit 58 is mounted.

The housing for recess 4'i also includes rear doors 59 which are pivotally mounted; edge-t0- edge, on hinges El and have louvers 62 to aid in ventilating the recess 47. The'doors lillli'e flush with the outer sheet metal plates 23 0f the cold box end wall 27 (Figs. 4 and5).

The refrigerant compressinguriiti 53: includes an internal combustion engine 63, anelectric motor 64. and a refrigerant compressor these elements being mounted on the frame 49 with their shafts 65 {it and-'58; respectively, in coaxial alignment, with the shafts I 85" and t i connec'ted' by a drive coupling 69; and with shafts 61 andtB' connected by a drive coupling 105 Between the motor fid and' the coupling 70 a double pulley ll is fixed on the shaft 5?. The exhaust from'the engine 53 is conducted through-apipe ld d'own- Wardly to a muffler '36 from whichitis discharged. The shaft 65 of engine fi'ii connects with the crank shaft of thelatter through aclutch TF which is controlled by a lever 18 to connect'or'disconnect the engine 63 with shaft 66' at will.

The structural steel frame 39 includes a-p'air of angle iron cross membersti) onwhich' the engine $3 is mounted by cap-screw 81. The frame 39 also includes a pair'of" angle iron cross members 82 on which the motor 64 is secured by cap screws 83. Frame M also includes a-pair ofangle iron cross members 85 on which the compressor 65 is fastened by capscrews'tfi. 7

A fuel'tank 99 for the engine 68 is' suspended from the frame (i9 and a channel beam- Q'i connecting frame channels 50';

Extending upwardly from one side of" the frame 49 are two posts 92', and; fromthe oppositeside of the frame, corresponding posts iit. Pivoted-"on the upper ends of posts 92 isa-rectangular bearing support 94 carrying bearings 95; said support being adjustably connected at its other side-with the posts 93*"by bolts seextendi'ng throughslots 9'1 in said posts. Journalled in-bearings- S5=is a shaftte which is held against axial movement by collars 9'9" and has fastened on the' outerend' thereof an air fan Hill and'on the opposite-enclthereof a double grooved'pulley' {M which is'connected with pulley H by endless belts 5622 The blades of the fan I00 are pitched so'that-when rotated in the normal operationof thecompr'essorunit 48 air will be blown fromtheright towardsthe left over the compressor (55 (Fig-3) Mounted on the frame 49 of the unit i8 at the extreme right end thereof close to the fan lilflisplates 33 which are identified as cold plates A and: V

C out of a series A, B; 0, B and E of said c'old plates which are embodied the structure of the cold box 20. The lower edgeof' cold plate A is connected by tube li3= with the 'upperedge-ofcold plate 13 while the lower edge of c'old-plate G is connected by a tube H4 with-the upper'e'dge of cold' plate E. The lower edge o'f' coldplat'eiEis 4 connected by a tube H5 with the upper edge of cold plate D. Cold plates B- and D are equipped with thermostatic elements H5 and Ill which are connected to and actuate control valves H8 and H9.

The lower end of the condenser I83 (Fig. 6) is connected by a tube I25; which is preferably about in. in diameter, through a reducer 62 and a tube I2! of approximately in. in diameter, to a receiver tank 128. The opposite end of receiver i28- is connected by a tube 529 with a dryer ISGwhich is connected by a tube iii to a sight glass 532 the latter being connected by a tube itlihaving branches H34 and we to the valves H3 and"! I9. When the temperature in the cold box 2Elis above a given minimum the thermostatic elements l it and i ll cause fluid delivered through pipes 13:3 and E35 to valves H3 and M9 to flow therefrom through pipes 535 and i3l', respectively, into the lower ends of cold plats B and D.

Tubes 5% and I if? travel parallel to-each other through a heat exchanger I33, the purpose ofwhich will be made clear hereinafter.

Secured to the lower face of the wall d5 (Figs.- 3'

and-4) is a service cord box I59 on which is mounted a thermo-responsive electric switch 54 which is connected by a tube E52 with a thermostatic element E53 mounted in the dead air space" between the rearmost cargo compartment 53 and the compartment 32 adjacent thereto (Fig;

The switch 555 is powered by current suppliedby a service cord ie l connecting with an ordinary lighting circuit to shut offthe motor td w-henthe temperature in the box fiii' dropsbelow a certain value and to start motor es when said temperature rises above a-given maximumvalue.

The motor FM isadapted to be energized bycurrent" supplied thereto by a service cord- 555: which is adapted to connect with a three-phase outlet provided in the service station orgarage where the truck Hi ls parked at'night.

Operation The truck iii" is especially adapted for the. wholesale delivery of dairy products packed in' cases in' which a substantial order including a case or more of goods is frequently deiiveredat each stop. The boxes or cases of dairy products thus transported .in the truck it rest upon the pairs'of rails 35' provided at corresponding levels" in all of the compartments tras'shown in Fig.

i. It has been found economical to keep the interior of the cold" box as refrigerated to the desired mean temperature of40 F. throughout" its storage at night in a garageso'that .it 'will' be unnecessary to'remove'any portion of a load taken out on a previous days' run which remains in the truck upon its return at night. Thec'o'ld box is thus ready to be reloaded'any time during;

the night with the product to be taken out on the next days run.

The unit d8 of the present invention may be swinging the lever i8 into its upright position in which it is shown in full 1ines-in Fig. 3;

this lever is not already so positioned.

When thus energized themotortil drives the compressor t's through' the coupling-{i9 and r0"- tates the fan so asto suck' airthroug-li tlie condenser I 03 and blow this air over the compressor 65, motor 6d and engine 63. The compressor sucks refrigerant, which may be Freon, through pipes H8, ill and H2 from the upper ends of cold plates A and C. This refrigerant gas is compressed in the compressor 65 and delivered therefrom through the pipe I84 to the condenser 56% which cools the refrigerant to condense this into a liquid which flows from the lower end of the condenser "13 through pipes I25 and i2? into the storage receiver 122. The refrigerant then flows successively through pipe 529, dryer iSil, pipe [35, sight glass 132 and pipes I34 and 35 to the thermostatically controlled valves H8 and MS from which the refrigerant is released and allowed to flow through pipes I86 and i3? into the lower ends of cold plates B and D, respectively.

From these two points the refrigerant circulates upwardly through the cold plates B and D from the upper ends of which it is transferred to the lower edges of cold plates A and E and from the lower edge of the latter to the upper edge of cold plate C. All of the cold plates A, B, C, D and E are thus refrigerated by the expansion of the refrigerant and the latter is returned through pipes H0, Ill and H2 to the compressor S5.

Before starting from the garage to begin each days run, the service cords i5 3 and H5 are disconnected from their respective outlets thereby de-energizing the motor t t, and are stored in the box 8%. The engine 63 is now started by an electric starting motor with which it is equipped. The lever i8 is now swung to the right, as indicated by broken lines Hit, thereby throwing in the clutch Ti. This causes the engine 63 to be connected with the shaft 65 so that the compressor 65 will be driven by said engine through shafts 66, 6? and 68. Because of the higher temperatures prevailing during the day and the losses of refrigeration resulting from the necessarily frequent opening of one or more of the doors 3! in the delivery of product from the truck, it is practically necessary to maintain the unit 48 in operation continuously While the truck is away from its home station. It is thus necessary to keep the engine 63 running throughout the day.

It is to be noted that the motor 615 when deenergized provides a ready transmission of power from the engine (33 to the compressor 65 While still allowing the engine and the compressor to be respectively located at opposite ends of the unit Q8 where these are directly adjacent to louvres 55 giving maximum access to the outside atmosphere.

The in-line arrangement of the elements of the unit 48 not only permits this unit to occupy a relatively small recess 4? formed in the rear lower corner of the cold box 2!! but the coupling of these units together by the couplings 69 and it which are readily detachable permit any one of the three elements 63, E4 and 65 of the unit 18 to be removed without disturbing the others, whenever this is necessary for the purpose of repairs or replacement.

While the primary function of the fan N39 is to cool the condenser H33 by drawing through this condenser air entering the recess 4'! through the adjacent louvres 55, this fan causes the circulation of air throughout the recess 41 and keeps the temperature of the air in this recess down to within only a few degrees above that of the outside atmosphere.

6 The claims are:

1. In a refrigerated body for use on a highway truck chassis having a frame and drivers cabin,

the combination of: a cold box having thick in-,

sulated walls and adapted to rest'on and be secured to the frame of said chassis behind the drivers cabin thereof, said cold box being divided by a series of transversely disposed cold plates into a succession of relatively narrow compartments, the side walls of said body comprising two like series of full height narrow doors hingedly mounted on verticalaxes along opposite sides of said box, said doors being arranged in opposed pairs, each such pair of opposed doors giving access to opposite ends of one of said compartments, there being an angled recess formed transversely in the rearmost and bottom insulated walls of said box at the lower rear corner of and across the full width of the box; and a self-contained refrigerant compressing unit housed within the space formed by said recess, said unit supplying compressed refrigerant to said cold plates to substantially uniformly refrigerate said compartments.

2. A combination as in claim 1 in which the housing provided for said refrigerant compressing unit includes the box walls lying above and forwardly of said recess, and sheet metal extensions of the vertical rear wall and side walls of said cold box which lie in the planes of the outer surfaces of said rear and side Walls.

3. A combination as in claim 2 in which said compressing unit includes a compressor, an internal combustion engine for driving said compressor while said truck is traveling on the highway, an electric motor for driving said compressor while said truck is standing overnight, and a manually operable clutch for positively disconnecting said engine from said compressor while said motor is driving the latter.

4. In a refrigerant compressing unit adapted to be mounted in a single recess formed transversely in a rear lower corner of a refrigerated truck body, the combination of: a compressor; an internal combustion engine; an electric motor; means for mounting said compressor, said motor, and said engine in a line with their shafts in co-axial alignment; means for coupling adjacent ends of said shafts whereby said compressor may be optionally driven by said engine or said motor and said shafts may be readily disconnected to facilitate removal of one of said coupled elements from said unit for repair or replacement; and a manually operable clutch for positively disconnecting said engine from driving relationship with said compressor when it is desired to drive the latter by said motor.

5. In a refrigerant compressing unit adapted to be mounted in a single relatively, long, narrow recess formed transversely in a rear corner of a refrigerated truck body, the combination of: a relatively, long, narrow frame; an internal combustion engine mounted at one end of said frame; a drive clutch embodied with said engine; a shaft extending from said engine which said clutch is adapted to optionally connect with said engine or disconnect therefrom; a refrigerant compressor mounted on the opposite end of said frame, said compressor having a shaft which is disposed in horizontal co-axial alignment with said engine shaft; an electric motor mounted on said frame between said engine and said compressor, said electric motor having a shaft which projects from opposite ends thereof and lies in co-axial alignment with the aforesaid shafts of 7-? said engine and said compress'oifi-andi is spaieed a'r--relativel y-= short distanne; reseeeti 1y: from said-' engine--and..eompressor=shafts; lin'gs uniting jiixtap'os'ed ends- 01 Safld compressorand m'otor shafts; and a lever- 5 manually controlling said 1 Gluten to d ise'onneet' said engine from said engine: sliaift -when eleo' tricity is availablefor sam nfotorto: drive said compressorand for reeonneetii ig sa ntis die-energized whereley powen from said; mot'o'r mayber. employed for starting saiii enginei:

6. Ina refrigerated body 'for'use'on a highway truck -ohassis'having' a ira'me anddrivers cabin,-

the combination of:: acold box having thick-in 15 sulated- Wall's and adapted tar rest; on andibe-se ci-iredto the frame of f said: chassis? behind th'e' drivers cabin tnereoi; said-mails includinga front wallg-a top walli a leariwa'll, anda awbottom wall; twodike s'eriesmf insulated-- doors hingedly on? veEtiiialaxes along opposite sides of; said: cold box so V as to substantially eomprise 'the side' walls tliere of, said doors being arranged irr-opposed pairsg':

a a, seriesof transverselydisposed- (fold plates 5 2 5710445 mounted 'with-m. saidbox spaced transverseplanest dividing thezinterion ot said b'ox into transverse oompartments, access to opposite; ends l -iieig'ht, nar om thick 20 I of ea 2h= 01" whioh is had by: the doors of one of aid pairs-of doors;- there: being a -recess termed-1 inz therearmost bottom corner of" said boxlandextendingafless the fu ll width of the box; and a self-contained refrigerant compressing unit operable means for disconnecting said engine: from said motor, said "un it supplying compressed refrigerant to sai'd cold': plates to substantially uniformly refrigerate s'aid c'om partmei'itse SELLS'I-ROM.

References 1 Cited= in1 the file of this patent UNITE? STATES PATENTS Numbeia Name Date 2,203,406? Dempsey, J r. .r i J une- 4 ,1 1940 Hawk'esnrr Oct; 16, 195k 2,575,939 Brouer Nov. 20,1951- 

